This invention related to a fitting useful for connecting two different assemblies together to enable fluid or gas transport therebetween and, more specifically, to a fitting designed to form an interlocking attachment with one of the different assemblies to prevent intentional detachment of the fitting when the other one of the different assemblies is removed therefrom.
Fittings used for connecting different assemblies together and for providing fluid or gas flow communication therebetween are well known in the art. For example, fittings having differently configured attachment end are commonly used to connect together fluid handling devices having differently configured or differently sized fluid transport attachments. Such fluid attachments are configured having a variety of different shapes such as tees, differently angled elbows, and the like.
Fittings used in fluid handling processing for the manufacturer of semiconductors, for example, are desirably formed from a nonmetallic material, as is all of the wetted members of associated fluid handling equipment. Forming such wetted fluid handling members and fittings from a nonmetallic material is desired to minimize or eliminate the potential for introducing for process fluid contamination into the system. The use of aggressively active chemicals in the semiconductor manufacturing process caustic have a known corrosive effect on metal surfaces, thereby otherwise producing a known source of process contamination.
Thus, fittings and fluid handling devices used in such fluid handling operations are preferably formed, or have wetted members that are formed, from a nonmetallic material, i.e., a chemical resistant polymer. In many instances, a fitting used in such application is interconnected between two fluid handling devices that are formed from nonmetallic materials. In such example application, the fitting can be threadably connected to a first fluid handling device at one of the fitting ends and can be threadably connected to a second fluid handling device at another of the fitting ends.
A problem that is known to occur in such a fitting application is that the threaded attachment between the fitting and the first fluid handling device can become unintentionally loosened when the second fluid handling device is loosened or removed from the fitting. The reasons that this occurs is due to the use of nonmetallic materials and the associated low coefficient of friction that exists between the nonmetallic materials of the fitting and both of the fluid handling devices. The low coefficient of friction between the fitting and interconnected first and/or second fluid handling devices is also known to cause the threaded connection with either device to become loosened during the normal process of fluid transportation between the devices, e.g., possibly caused by thermal cycling and/or process element vibration and the like.
Fittings used in the above-described application are, therefore, known to become intentionally loosened during the fluid transport process and during fluid device removal. If left unchecked, the loosened fittings can produce an environmental or a personal safety hazard if loosened to the extent that process fluid is allowed to escape to the environment.
It is, therefore, desired that a fitting be configured that would reduce or eliminate the possibility that it could be unintentionally loosened during normal fluid transport operation, or device removal. It is also desirable that such fitting be capable of providing an interconnection between fluid handling devices having differently sized fitting connections. It is further desired that such fitting connection be relatively easy to use without the need for specialty tools.
Fittings of this invention provide both a leak-tight seal and a interlocking attachment, when connected to a fluid handling device, to prevent unintentional fitting loosening that could result in leakage to the surrounding environment. Fittings of this invention generally comprise a body having a substantially hollow transport passage that extends between a body first end and a body second end. Each of the fitting body ends are adapted to accommodate attachment with respective fluid handling devices. In an example embodiment, the fitting body ends are configured to accommodate attachment with a threaded members of such fluid handling devices.
The fitting includes a means for grasping the fitting disposed along an outside surface of the body. The grasping means provides a holding point on the fitting body that is used to rotate the fitting relative to a fluid handling device, e.g., for providing a threaded engagement therewith. An interlocking attachment member is disposed along an outside surface of the fitting body and is adapted to form an interlocking attachment with a complementary member of a fluid handling device when the fitting is connected thereto. In an example embodiment, the interlocking attachment member comprises a plurality of rachet teeth that are configured to register with a complementary fluid handling device member.
The fitting body first end includes a tongue that projects axially a distance therefrom that is sized and shaped to provide an interference fit within a groove disposed within a fluid handling device opening. The tongue-in-groove attachment provides a leak-tight seal between the fitting the fluid handling device.
Fittings of this invention provide both a releasible interlocking connection with a fluid handling device that will not become unintentionally loosened from fluid transport operation of loosenin of a connection at the fitting body second end, and a leak-tight seal between the fitting and the fluid handling device. Further, fittings of this invention can be configured having differently sized first and second end, thereby enabling the fitting to be used to provide a transport coupling between differently sized attachments of fluid transport devices.